docs: def dispatch(self, request, *args, **kwargs):
          ''' If a list of customers or groups was passed, then parse it '''
          ids = request.GET.get('customers')
          groups = request.GET.get('customergroup')
          self.customers = None
  
          if ids or groups:
              # Initial filter applies to no one but allows appending by logical or
              filters = Q(id__isnull=True)
  
              if ids:
                  filters = filters | Q(id__in=[int(x) for x in ids.split(',')])
              if groups:
                  filters = filters | Q(groups__id__in=[int(x) for x in groups.split(',')])
  
              try:
                  self.customers = Customer.objects.filter(filters)
              except ValueError:
                  return HttpResponseBadRequest(_('Invalid customer ids passed'))
  
          return super(SendEmailView, self).dispatch(request, *args, **kwargs)